My firm, Davis Polk & Wardwell LLP, has launched a corporate governance blog. This has a particular focus on U.S. corporate governance issues. The link is here:
http://www.davispolk.com/briefing/corporategovernance/
The Board Director Training Institute (BDTI) is a "public interest" nonprofit in Japan dedicated to training about directorship, corporate governance, and related management techniques. It is certified by the Japanese government to conduct these activities as a regulated nonprofit. Read a summary about BDTI here, and see a menu of its services for both corporations and investors here.